There's no reason to wait an hour for the Prime to work. Just add it to the tank before throwing in the new water, and you are good to go. Also don't have to wring your sponges that often, but that's a personal preference.
I'd recommend ditching the buckets and investing in a bigger container with a pump. Lifting buckets becomes a serious risk to your mental health as a fish keeper.
Cheap example of what you can put together:
Container - 20 or 32 gallon Brute trash can, $23 or $25 at Home Depot
Pump - $20 fountain pump on Amazon
Tubing - 10' of 1/2" braided vinyl tubing, $15 at Home Depot
Heater - not necessary, but use a cheap one if you want