Having full-timed in a 37' fifth wheel from 2003 to 2007 and then our 98 Airstream 34' from 2007 to 2010, we made a habit of never ever putting solids (you know what I mean) down the black tank. We took a short walk to the RV Park's public toilet to do number 2.
Recognize that our rig was mostly parked stationary for months at a time and having heard the horror stories of others, we did not want to repeat them on our watch, in our black tank.
This approach has worked out well for us. You may not enjoy the trip, but to us, it's not much different than walking to the RV Park Laundromat.
Would you rather have a mansion full of money or a trailer full of love?