Now is the time for me to point out something I've discovered. I knit a bunch of dishcloths with size 7 needles and they looked wonderful, however I found they didn't dry when used! I wanted something that dries fast so you don't get that icky smell and there's less time for bacteria to develop. (at least that's my thinking) So I knit a few up in size 9 needles. Big difference and those are the ones I use now. When they are washed they look just as good as the ones done on smaller needles, too. Not sure what I'll do with the tighter ones...maybe dust cloths.
Anyway, go ahead and give it a try.