Have a serious roach problem can you spray viper on the wall as well and would it be harmful if you touch said wall after product has dried?

I would test it on a small portion of the wall to make sure it would not affect any paint/paneling.  However, I feel that if you will spray the baseboards, around windows, under sinks, behind fridge and washer/dryer and door thresholds, you would not have to spray the walls.