If you want to clean off aiptasia and other organic matter from rock, then IMO the easiest way to do it is with a bleach bath.
What I do is soak the rock overnight in a combination of 5 gallons of freshwater to 3-4 cups of bleach. If one overnight soak doesn't take everything off, do it a second time.
Then rinse the rock good, and do another overnight soak in a freshwater and a strong dechlorinator solution. I do 5-6 times the recommended strength.
I like to use API Tap Water Conditioner. Can be bought at many stores such as Petsmart. Some will use Prime.
If the rock is older rock, ( been used for several years), consider a muratic acid soak. It will help remove surface phosphate soaked into the rock.
I like to use 2 cups of acid to 5 gallons of water. Don't use any stronger or it can dissolve the rock completely. Plus I would only do this on larger pieces of rock.
Wait until the bubbling has stropped and dump the water and rinse good.
I like to let it air dry for a day.
Don't pull the rock from the bleach bath and do the acid bath. The possibility of toxic gas is pretty high.
Plus don't do either of these soaks inside. Do it outside. Use eye protection and rubber gloves and stay upwind of the fumes.
I've done this method of cleaning rock several times over the years and it's what has worked best for me.