Starsan goes a long way so your suggestion is OK but a more economical approach is to use a bottle tree with a reservoir of starsan with a bottle sprayer combined. Search for the best price combination of something like
this . Combine this with a 1 litre bottle sprayer and one of the bottle versions of
these and you pretty much have it covered.
If you already have a bottle brush but like the idea of using a drill you could cut the loop of the handle off and stick that in your drill. Suddenly cleaning and sanitising bottles looks less daunting. But I bet you end up kegging eventually.
EDIT:
This site appears to offer what you need at a reasonable price.
