The mop can be selected either by scrolling the mouse wheel, by pressing "1" on the keyboard, or Dpad up on a controller by default (this can be changed in the options menu).
Using the primary trigger (left-click by default) with the mop selected will thrust the mop forward and back. If this is done on or near a mess, the mess will begin to fade and the mop will absorb it. Depending on the size of the mess, it may take multiple swipes of the mop to completely clear it. The mop can be used to clean up messes on any reachable area on walls, ceilings, floors, or stationary objects.
The mop creates a small splash radius each time it is used, meaning players may clean certain messes without ever actually touching them with the mop (e.g., mopping a wall may clean part of a mess on the floor). Each mess decal has a hitbox, which may extend outside the colored portion of the mess. With some messes, the hitbox that removes it may be off-center, or not intuitive for new players to find.
As the player uses the mop, it will become dirty in stages, until it is fully saturated. The degree of mop saturation can be gauged by the color of "mop drips" (mess dripping off the end of the mop) and the degree of colored mess on the mop itself. When the mop is fully saturated with mess, attempting to clean an area will instead leave a large splatter the color of the saturated mop, adding to the existing mess.
Mop drips are turned on by default, but may be turned off in the main menu, under "Options", then "System".
The stages of mop saturation with blood are shown below. Stage 1 is a clean mop, and stage 8 is a saturated mop. Mop drips begin at stage 5. Note that mopping some especially dirty areas may saturate the mop more quickly than shown below.
Cleaning the Mop
To clean a mop, it must be "used" on a source of clean water, normally a bucket (although toilet bowls may also be used). The player must take care not to knock over a bucket while cleaning a mop, as this will create a mess.
Buckets with clean water can be obtained from the Slosh-O-Matic, and can be used to clean a mop as many as 6 times before becoming completely dirty. Water inside a bucket will become progressively darker colored as it dirties, and stains will appear on the outside of the bucket. These stains become darker as the water gets dirtier.
When water is completely dirty, the bucket becomes a new source of mess, and must be disposed of. If the player uses a clean (or non-saturated) mop on a completely dirty bucket, the mop will become fully saturated with mess the color of the water in the bucket. This may also occur in the dirty water found in the trophy room of the Office or in the Waste Disposal level, as well as in bloody toilets in Evil Science, Revolutionary Robotics, or the Office.
Buckets containing water that has been used to clean a mop even one time are detected as organic trash by the Sniffer. Knocking over such a bucket will create the same mess as a fully saturated bucket of water.
Using the mop on or near an object will push the object away from the impact point, so some degree of care must be taken to keep from inadvertently knocking objects over or sending them flying in an unpredictable direction.
Using the secondary trigger (right-click by default) will cause the player to swat with the mop, hitting walls or objects with much greater force. This method will not remove any mess, but it can be used to "sweep" small objects together (in the absence of a Broom).
The mop may be used to free objects stuck in tight spaces or partially clipped in the level's geometry. The force of the mop may affect objects on the other side of a solid wall, cleaning mess or freeing stuck objects. (This is particularly useful in Uprinsing, where objects may become wedged under desks.) Either trigger (left- or right-click) may be used for this purpose.
Several unusable mops are found in the Office, and one can be found in Uprinsing. These mops behave as regular items, which can be picked up and moved, but not taken into inventory. These mops are prone to clipping issues which cause the front end of the mop to get "stuck" in the floor, against a wall, or on a shelf.
A vendor has a small chance of dispensing an advertisement for the mop. The advertisement reads as follows:
- Black Wheel Industrial Sanitation Inc.
- The new A-Series Space-Mop is here!
- With its sleek ergonomic design and Haladium Yellow paint job.
- The new A-Series Space-Mop is a work of art.
- With just a single swab of its tentacle design head, it's goodbye mess! Proven to remove all tough stains, no matter the cause.
- Pre-Order now for only *55.99 Vaders!
Shadow Warrior Mop
The Shadow Warrior level uses a unique bamboo-handled mop with a round mop-head. Only the appearance is different, however, as the mop functions exactly the same way as the standard mop.