Others have pretty well answered it all, ours is 9 and she's been going on month long road trips since conception...she was likely conceived ...lol, never mind ...
I'd like to add, flushable baby wipes....not black tank friendly...I didn't know DW was flushing them...after about 2 weeks on the road the stench was terrible...I would use a thief to fill the black tank with hot water and pine sol from a shower or gas station bathroom and drive for. Few hours sloshing about..while I was able to manage the smell, and get most of it out, it was over a year and I would still see the odd wipe ....