I usually just give the salsa a light turn through the pan to warm it over and get the butter all through it. Never had it raw. Not really game enough to try it yet.
The trick with frying sausages is to fry them S-L-O-W-L-Y so the heat can get all the way through. Otherwise you end up with the Mummified Backyard Banger.
RE: Sausage fail