The drop ins would total about $1.00 per flush if you do it every flush. Also DO NOT leave the black tank drain valve open when connected to sewer, the gray can be open til a day or two before dumping black, dump black first then rinse hose with gray.
Sorry! You'll have to admit to her she was right, just man up & tell her, it'll only hurt a minute. LOL!
Danny & Linda
Sold our '13 Thor Redwood 36 FB
Currently RV & truckless