Tank sensor cleansing

Am in Yuma, AZ, for couple more weeks.  I stopped by a store today that had a mixture of things, and also a fairly large RV section.  Had specifically went in there to get a piece for my new Reverse Osmosis water purifier.  I had avoided this store as it didn't look overly appealing for me, but was pleasantly surprised.

In the store they have a whole bunch of chemicals to clean, deoderize, and all sorts of other things tank related.  Thought about getting one to clean my sensors, the ones that measure how full the tank is, but put it back on the shelf and continued browsing.

Afterwards, one of the people who worked there, a slightly older gent, came up and asked if needed anything.  I pointed to my brass compression garden hose fitting and said was looking for a plastic version, which they didn't have.  He then informed me I would also need a little plastic insert to slide into the 1/4" plastic pipe, so got that little part.  This plastic insert allowed the metal crimp piece to put pressure on the plastic hose without crushing the plastic hose.

On a whim, asked him what is recommended to clean the tank sensors, and to my surprise, he said that chemicals on the shelves were pretty much useless.  Sure, they might do the job, but might not.  He then preceded to regale me with wisdom of an old seer, of an aged RV repair guy who used the following two things:

Liquid Dishwasher detergent / soap

Use about 1 cup per full tank.  It MUST be liquid, no if's, and's, or butts...  Brand doesn't matter so I went to get some eco-"friendly" version at Walmart.  It was explained to me that the dishwasher detergent has a powerful degreaser, along with good detergents, that will clean the sensors by dissolving / removing any gunk on them.  Normal hand dishwashing soap WILL NOT work.

Calgon Fabric Softener

Use about 1 cup per full tank.  This MUST be Calgon, it was conferred to me that it can't be anything else as they don't seem to work.  What was passed on to me, and now you, is that this coats the sensor, after it's cleaned, preventing gunk from building up again.

Application

As eluded to above, it should be done in this order:

1. Add 1 cup liquid dishwasher soap after emptying tank(s) and closing valve(s).  I would add some extra water to tank (some people say 20%) to help keep a clean tank
2. Test sensor as tank fills up
3. Fill tank full, or above the "full" sensor
4. I would let tank sit above full as long as feel comfortable
5. Empty / drain tank(s) in normal manner
6. Test sensor(s)
7. Repeat 1-6 until sensor(s) function normally.  For me, when tank is empty, none of the lights light up.  When it's full all lights light up.  Yours may vary
8. Repeat step 1-6 one more time (as safety measure)
9. After second time of fully working sensor(s), start using calgon after empty tank(s)
10. Add 1 cup of calgon fabric softener after tank is emptied (and valve is closed), and add some water to help it out
11. I was given no further instruction / wisdom.  If sensor problem reappears, add more liquid detergent as necessary, then use calgon after problem cleared

My experience

Learned about this today so don't know anything other than adding my liquid dishwasher detergent to my black tank.  Am due to empty black tank in couple days, maybe a week, so then will add to grey tank too.  Just emptied grey tank recently.