The configuration and the space consumed by the Robot will be the most significant challenge. Need a customized trussing system to enable the robot to move in the 3D space of a bathroom. Most efficient would be a track-based, ceiling housed system--depending on the size of the bathroom--think claw games you see in arcades. This would be a semi-perm install however.
Need a tooling system on a central locomotion/power actuating system. If using one central robot system, the tooling system will allow you to change "heads" between the specialized tasks of lifting lids vs spraying disinfectant vs wiping around corners.