...Can you suck dick round a cathater?...
Loving the very formal and professional language (not to mention the orthographic accuracy) - nothing like it for credibility...
...What if your client needs the toilet during a booking and their carer isnt' there - can you hoist them from the bed, into a chair, get them to the toilet and back again?...
I'm up for that. A way into a career as a care-worker for me at long last!
...Or you could require the presence, during bookings, of an appropriate party to perform these duties, should the need for them arise.
You have yourself hinted at this as a solution to the situation.
FYI, if I were a care-worker, I would perform those duties without complaint (as I did when I worked in a care home and as a home-help 26 years ago).