Right you lot - be honest now. If you had a catastrophic no.2 that painted the pan, would you make good the damage using the toilet brush?
I realise a communal toilet brush is the not the most desirable object to pick up but a thorough hand wash afterwards and all's well.
Personally, I would clean off after myself but it would appear that I'm in the minority where I work. Most mornings, the traps resemble sacrificial chambers for brown blooded goats.
I believe in leaving things as I'd like to find them.
Your attitudes and experiences....