Success!
I just came inside to share virtually the same experience you had. Pulling the 'mold' out is a near heart attack.

I put two coats of releasing solution on a 7/16" glue stick (just dipped it into the bottle, let it dry, did it again)
Drilled two 1/2" holes (reamed a bit) 1" apart in a piece of scrap that was a little thicker than 1/8".
Not yet having the sleeve I spiral-wrapped the end of the glue stick with 1-1/2" fiberglass bias tape (taped both ends with masking tape to hold it)
Then I inserted one end 1/2" or less and put the rest of the wrapped glue stick through the other side. I have long 9"? hot glue sticks handy so that's what I used. The regular sized ones would work the same.

I used West System 105 and Fast Hardner. Of course I didn't wait long enough before starting to pull. This crushed part of the epoxied sleeve a little--which also roughed it up. I stopped and let it cure. The crushed area inside is a bit rough, but the rest of the tube is smooth.

Results:
1. The hot melt glue stick is still smooth as is the inside of the fitting. The epoxy had not effect on it,
2. Exactly as was your experience, nerve wracking to pull out. I found that I had to break the weak bond/friction/voodoo holding the glue stick to the epoxied glass. It seemed like it wasn't going to move until it did.
I think next time I'll leave more glue stick on each side so I can stretch and twist each side to loosen it up. I'll bet you could use a pivot block and pliers to yank it out without hurting anything.

3. My fitting results:
1" center to center on the holes in the deck. Height of the fitting 'under deck' is .653" (a little more than 5/8"), width of 'tube' with bias tape and one coating of epoxy is 9/16".
The gap under the arch is .153" high and .3" wide. I think it would be a good idea to make this a little large so it can be used as an under deck tie on.
4. inside tube is 7/16" which is large and a bit too big for 1/4" line. The line easily threads right through, I even doubled it, and that went through no problem.
Definitely a Green Light. ( I would probably prefer if the inside were 5/16 or 3/8", but I can live with this.)

I also think that I can make these as 'parts'. If I leave the epoxied tube sticking out of a strip, I can retrofit my other kayak by drilling over sized holes buttering them like ceramic tiles, fitting them then filling in the gaps on the deck with dookie-smutz and sanding them off.

I also might try to make rudder cable tubes with this method. I think you could even run one bare cable and one in a sleeve through one of these tubes. I would glue the tube to the underside of the deck. The rigidity would eliminate a lot slack and eliminate interference and damage of a moving cable with dry bags in the hold.

If there's interest, I'll post pictures when I install the Maroske's on my Mystery deck.

Will

then pulled out
: the clear tube which never comes out easy. I've done >40 of
: these fittings now and every time I go to extract the clear tube
: it is a scary fight. I've never had one break off inside the
: fitting but I've often wondered if it was going to happen. I
: always grease them with Vaseline but I never like to use very
: much for fear of contaminating the epoxy.