I can’t speak for Wisconsin, but next door in Minnesota, we like to crock pot brats, you keep your pre-packaged crap, we go to the butcher for real ones. Add jalapeños, onion, bell peppers and whatever else sounds good in a half beef half water mix, use real beer no lights, set on warm setting for 8 hours minimum, then toss on the grill to finish with a char. Put all the add ins in a foil pouch on the grill to use as toppings. Poke brats in maybe 10 spots before crock pot so they better absorb flavor.
But I’m also curious what the true Wisconsin way to do it is.