You are the one to do the cleaning, no fish will do it for you.
These fish are more sensitive than some of the other more prevalent plecos, and won't fare well in poor water quality. They need clean water.
One thing that may be of useful knowledge for you, since the use of a powerhead or wave maker is advisable with these fish, if you use sand substrate instead of gravel, the debris won't sink into the substrate and instead the current in the tank can be manipulated so that the debris is pushed towards the filter. Gravel will trap debris and make more work on keeping things clean, sand like pool filter sand would be best. Play sand works too, some folks find it too fine, I prefer it, but that's your decision.
In your filter I'd recommend having a permanent media such as sponge or ceramic and then also a disposable media like filter floss which will collect that debris and can be thrown out and replaced when full. Canister, hang on back, or internal filters are better with these fish, a sponge filter (though reliable) may not keep up with the mechanical filtration you'd need with these fish.
They'll bicker over territory if kept in groups, which they can be kept in groups if you have the filtration and space to support it. A 55 gallon with a canister could house a pair or so, and allow several rocky crevices for them to claim. More crevices than fish so they won't have to fight over a space.