I bought a pool vacuum hose - they come in very long lengths and are flexible. I put one end on the garden and bring the other end inside. I tie that end to the back of a chair then I use the ordinary tank vacuum/syphon thingie - I get it started, push the end of the syphon tube down the pool vacuum hose and vacuum the tank to my little hearts content! And as a bonus, my garden loves the water and nutrients it gets from the tank water.
Then I bring in the outside hose and use it to refill the tank. I squirt in some chlorine remover if I can smell chlorine in the water but otherwise I don't bother. I have one of those trigger type nozzles on it so I turn it on at the tap, bring it inside and put it in the tank, then start the water running.
Piece of cake - no buckets and hardly any splashing.
Cheers
Jude