Revisited an SKS for the first time in a while last weekend.  OMG M67 is good ammo!  Amazing how it is older than me and still goes bang every time with decent accuracy.  

Hot humid and sticky weather was no problem.  Brought a bottle of cheap Lowes bought multipurpose oil and hosed her down before and after.  Waited 2 days to clean and not a micron of rust

Oiling over the corrosive salts will keep the rust away for a while but oil evaporates & as soon as the moisture gets through the oil your gun will rust.
A rinse with water will flush out the salts, then clean & oil as normal will keep the rust away forever.

He speaks the truth. I thought the same thing until I went to check one day and saw rust in the gas tube. Flush the salts away with hot water then clean as normal.

Even better.
Make up a solution of  Ballistoil  and water.
1 part Ballistoil in 9 parts water.  This is also known as moose milk.

I use this at the range or very soon after I get home.  Swab out the bore gas tube, bolt etc... Then clean as usual.
You will find that just this is very good by itself for cleaning.

If you are busy you can just do the initial cleaning and come back to it in a few days.
The water evaporates and leaves a fine coating of oil behind.

I flush with hot soapy water then wipe down & re-lube with Ballistol, Most of the Ballistol will dilute with the water and take a lot of carbon with it.

I like the Yugo M67 too. Got a small pile in the shop. But last crate I saw for sale online was $500. Getting close to the cost of Privi Partisan, and that's a more accurate round.

I bought around 2K rounds years ago when it was dirt cheap.   I have shot my M67 years ago, but stopped shooting my SKSs until recently.  

Never had any issues with corrosive ammo because I always fully take down my milsurp rifles after shooting and submerge all the smaller parts in a bucket or jar of Ed's Red.  The rest of the metal parts get liberally sprayed and wiped off with the same solution.  Even using synthetic ATF, it is less than $30 to make up a gallon of it and it lasts a long time.   I do not have a parts washer, but use coffee filters and a funnel to filter out junk and carbon from the solution before I pour it back into its container.  Ballistol is an excellent product and great for corrosive ammo or bp shooting, but is not as aggressive of a cleaner and solvent as Ed's Red.  The best thing about using Ballistol is that you can use it on every firearm you own and it will not mess up wood or plastic.

I only shot Yugo 7.62x39 thru my bolt gun while it is corrosive and cleaning bolt gun is easier, accuracy is not much better than Barnaul and Yugo is more expensive. If your range does not permit steel case ammo with bi-metal bullets, Yugo is an option compare to more expensive brass case 7.62x39. It is not reloadable, attractive if you don't reload.

Do you guys disassemble/clean the gas tube each time after shooting corrosive ammo?

I do, but only because it's no trouble to do so. If I had something like an ultimak tube that made it trickier I'd probably just run water through it.

If you mean remove the gas tube from the rifle then yes, ALWAYS! Failure to do this is probably the biggest cause of corrosion related failure. Make sure you clean the tube AND the gas port with warm water to dissolve and carry away the corrosive residue. Then a very light oil to keep things from rusting.

If you mean disassemble the gas tube itself from the wooden handguard/cover. No, that is not necessary.

you can still get Yugo crates from classic and sgammo in the mid $300 delivered

This is my favorite 7.62 ammo by far

M67 is great ammo. Corrosive but good. I've always just hosed the guns down with WD40 and never had an issue. My only 2 complaints are it's Berdan primed and that darn red primer sealant flaking off.

I'd love to get my hands on some. Maybe next year...

Yep.