micky wrote

Someone on Freecycle gave me a nice tv, pretty old,
but comelete with owners manual and remote control.

The remote works fine except for the buttons used the most,
volume up and down, channel up and down, power, and muting.

That's pretty common with older remotes.

I took it apart and expected to find oxidized contact points,

They are normally gold plated so don't oxidise.

but no. Instead those buttons, on the circuit board
and on the buttons, are shiny and a little bit sticky.

Likely someone managed to spill something on the remote.

I forced myself to taste it, but I don't taste anything.

Likely because it has been there a while.

3 other buttons have a little of those,
but no more than 4% of any button.

What is this, how does it get in there,

Likely someone spilt something on the remote.

and [what do I do about it}?

Wash it off.

I have DeoxitIT, what I've read is the best, but I guess I've
never used it before, and it didn't remove the stickiness.

Not surprising that it didn't.

Not only that, these contacts aren't copper-colored,
and as the name impplied, it's really to remove and
prevent oxidization, so I switched to isopropyl
alcohol and that did a good job.

So I know what to do about it, but what is that stuff? Finger oil?

More likely spilled drink. Finger oil isnt sticky.