I have yet to work at a gym or studio that didn't require me to do some amount of cleaning up after myself, after my clients and around the gym in general. It's just part of the job. However, as the owner of a studio, I'm astounded at how often we must revisit the chores list during staff meetings.
I'm not going to defend the virtues of wiping down BOSUs, cleaning mirrors or emptying the trash. I understand that that's not the reason you signed up to be a trainer. Remember, though, that the impression cleanliness - or non-cleanliness - of the studio or gym makes on the client is a direct reflection on you. You could be the best trainer in the world, but if your space is filthy, you will lose clients. And when money is tight, you don't want to give them any excuse to take their business elsewhere.
Pitch in, do your part... and even a little more. I guarantee your extra efforts will come back to you.