cleaning out black tank and toilet bowl

Vinegar sure cleans the water ports in the home toilets. I'd inject vinegar with the water pump in the RV if I thought it needed it.

Deodorizing your black tank (and expecting it to stay deodorized and fresh) is a path to madness. Keeping the odors out of your RV is rather more practical, and basically means making sure your plumbing system (and its seals) is working properly.

I use an ordinary toilet brush to clean the bowl of the toilet, and if needed wipe it down with a rag, just as in cleaning any other toilet. I have a spray wand that I use to rinse out the riser part of the toilet and the black tank from time to time. I do not skimp on water when flushing, and limit what goes down the toilet to the usual "P" things (paper, poo, and pee). Beyond that, I don't really worry about the black tank much at all, and it seems to do just fine.

We had a toilet brush right next to the toilet. Our toilet was plastic so the brush got used a lot. We had a bowl cleaner that was used once in a while. Not really needed often.
The black tank is never going to be fresh. All we ever used for 11 years was water and whatever toilet paper my wife liked. Not septic safe, not RV,
just whatever.

I drop the Walex blue tabs in mine after every dump, along with a couple toilet flushes of water. No smell, and no build up in the tank (I can see the bottom of it through the toilet).

I was a bit alarmed this past weekend when I went to dump and I got a rush of junk out the hose, a brief pause, and then (thankfully) another rush and a complete dump. Not sure what was hung up, but I'm glad I didn't have to manually remove it. I did let some presumably liquid waste sit in there for a couple of months between dumps but someone may have sneaked in a dookie without me knowing. The kids use it as a clubhouse when it's docked at the house but I tell them to come inside for #2.

All we use is water. Plenty of water is a black tanks friend and yours as well to prevent odors and ensure solid materials, you know what I mean, are flushed when you dump.

If you don't have black tank flush for your tank or don't have acess to a water tap as at most dump stations, but do have a nonpotable source as at most dump stations and are not holding up others, I will fill a couple 5 gal buckets to dump through the toilet to flush any remaining solid deposits. I then close the valve, fill another 5 gal bucket and dump that down the comode to prime the black tank.
No sanitizers or chemicals are needed.

Lets face it you don't pour chemicals down your home toliet unless you have a septic system and then maybe a emzyme digester, though even those are not needed.

As for cleaning the toilet bowl, which is not an area of my expertise, DW uses the same as in the home toilet.