That would work, provided that you have maintained a coat of paint on the body and no bare wood shows.
However, you can go to any auto parts store and get Dupli-Color touch up paint in rattle cans - it's acrylic lacquer - and paint it yourself for much less.
Put a compatible primer coat on, then at least two top coats. Then wet sand with 1000-1200-1500-2000 wet & dry sandpaper, being CAREFUL not to sand through the finish, and polish with 3-M Finesse-It II machine polish on a buffing wheel.
Dan Erlewine's books on guitar repair explain all this.
BTW - if you're one of the faithful fanatics who think that the less paint on a bass, the better it sounds, then you don't want to do this. It obviously adds multiple paint layers. But as you say, this is a practice bass in any case, so it's probably not a big deal.
BTW - I did the same practice run with a bass I found in a pawnshop, and it turned out great. Maybe the result will encourage you:
