I keep a small mesh strainer next to the sink. Add a little water to the leftover grounds, swish, pour into the strainer, then into the trash (or compost if you have it).

I was gifted a litter genie and I wish I'd had one all along. They make bags for them but a standard kitchen bag works fine and the design contains the smell. I have one cat, scoop every day, and take out the bag once a week. They run about $20.

I worked there briefly decades ago so I don't know if it's the same routine but I'd have to check in to find out what section of the park I'd be working in, then get the uniform (there was sometimes a wait for this) and change into it before walking to my station. All that could take 45 minutes or longer and it was unpaid.