There are serveral companies offering yacht charter. But the closest to a small dinghy that I could find would be a Lis-Jolle at
Bodensee Segelschule Wasserburg, and while that is a dinghy, it is still a two-handed boat.
I'd be interested in places that offer racing dingy charter at the Bodensee, too.
BTW, no problem with a Laser, but note that you need a license to pilot sailboats with a sail area larger than 12 sqm on the Bodensee.
(it may be possible to get a temporary guest license if you have an appropriate non-Bodensee license)