Yup, I've cleaned several tanks tank way. I put them on the porch, fill them with warm water, pour in a gallon of white vinegar, put in a couple of powerheads I want to clean and let it run for two days. After two days I drain it, spray it out and and all the coraline algae falls off with a sponge. I rinse and done!
I do the same thing with Stop & Shop lobster tanks at work except I use non-scented bleach and let them run overnight only.
Tank is pretty clean except the corner overflow... but I will try vinegar and hot water there. The stand is loaded with salt spray.... normally I use murphys oil soap on wood... would that be a no no? I probably will not be putting the sump under the stand.