use a towel, if its still not to next users standards, most gyms have paper towels and desinfectant, let him do it
biggest peeve though is not sweat, its leaving weights all over the show and not unloading machines
if you just did squats on the smith, leaving 3 plates a side, and the next guy is gonna do presses, he's gotta unload the thing unless ronnie trains at your gym and its delt day