A Python is a first rate piece of equipment. I have one with a long tube (25'?). To drain the tank, I use it like a regular syphon and drain water out the back door into the back yard. To refill the tank I hook it up to the kitchen faucet.
For day to day cleaning I use a battery powered gavel vac called Mr. Cleaner. I like it a lot. Here's a link for it:
http://www.drsfostersmith.com/product/p ... atid=12753
For picking up the larger "stuff", I use a little fish net.
And on the gravel, there are two good reasons not to have it in a turtle tank. One is that it's very dangerous - turtles eat it and it stops them up. Second, it's hard to keep clean. A tank bottom with just a few river rocks and decorations is much easier to keep clean.