So I am looking into getting the Ultimak. It seems as though it would be a bad idea for your zero to remove the apparatus every time to clean. But if you leave it on, and pour the hot water down the tube, won't some moisture get stuck between the rail and the gas block? I have seen rust start to form there before, since it's so tight and steel-to-steel. Obviously the Ultimak is aluminum, but I would think the steel would still be more prone to rusting.

What do you do? I could see in a SHTF situation, shooting corrosive ammo, this would suck.

it does not contact or connect firmly to the blocks. its aluminum so it wont rot away.

i just pour boiling water down the tube and block. scrub with a 12ga shotgun brush. i have not removed it to clean in 5k rounds. i only removed it to change hand guards.

no rust or rot. worry not

It's weird to hear if you don't have one, but it actually doesn't touch the gas block or the rear sight block.  It is hovering between the two only clamped on by the barrel.  I think this is why some people report an increase in accuracy.  There's no forward or upward pressure exerted on the gas block.  

I have 2 TWS doglegs and 2 ultimaks.  I like em both the same.  The Ultimaks are on 7.62s, though, which I don't shoot corrosive out of.

i would say i saw an increase in accuracy over the standard gas tube. maybe a .50 improvment at 100m with irons

but yeah, it sounds odd to describe it, but it does not contact either the forward or the rear blocks.

I was under the impression that anything clamped to the barrel will decrease accuracy, I have heard reports of decreased accuracy when people install quadrails that clamp to the barrel.

Couple things to consider is the quad rails still utilize the factory gas tube wedged between the blocks and the amount of weight a quad rail adds to the barrel empty and loaded with stuff.

A ultimak weighs little in comparison and does not contact the blocks so the barrel is still allowed to "float" in relative terms to ak barrels.

If only ultimak was available for a PSL I'd be first in line

I very rarely clean my gas tube or gas block. Basically the only time I do is if I shoot corrosive ammo.
After shooting corrosive ammo I just field strip the rifle then take it out back, spray it down with a hose, getting plenty of water down the barrel and gas tube, then dry it off with an air compressor. After that I just do a normal cleaning/lubing.

Solvent soaked bore brush to clean and a bore mop to dry it back out. Very light coat of oil afterwards and you're done. I'd suggest cleaning it before the bore since the solvent tends to run into the barrel thru the gas port. Never had a problem with cleaning this way after I switched to a railed HG.