I just came in from the garage where I put a new tire on the rear wheel.
I used the "Zip-Tie" method and it worked great.
I inflated the tube inside the tire enough to expand the tube into the tire.
Then I strapped the zippies around the tire and cinched them tight, pulling the beads together as one.
The valve stem was held tight by the beads and I just fed the valve through the rim hole and pushed the tire all the way into the rim well at the valve.
I then screwed the nut on the stem some so it wouldn't pop out and then I put a zippy around the tire and the rim to hold the tire in the well.
Then I was able to push both beads over the rim for more than half the tire and used one tire iron to pop the rest in a few inches at a time. I had done the front tire last night the same way (first time ever using zippies) and I did that one dry, with no lube and it was easy. For the rear I used dish soap to compare and it was just as easy even though the rear tire is much stiffer and wider. FWIW I timed how long it took at my usual turtle pace and it was 5 minutes from tire zipped and sitting next to the rim, to tire completely on the rim and ready to remove the zippies.
I do also have a valve stem puller that threads into the valve (replacing the core) and I have always used it to fish the valve stem through before but with the zippies I didn't need it.
As you have found, trying to get the valve stem through the rim with one bead on the rim is an exercise in character.
That means if you don't turn green and get hulking mad and throw stuff around, you have a good character.
I don't. My hands are too big and the bead is so stiff!
So, a long worded response to your simple question but I recommend pulling the tire off the rim and try the zippie way.
Otherwise, the way I used to struggle and fight to get the valve in required Hulkifying angry strength.
And that always resulted in lots of skin torn off the backs of my hands and fingers.
The valve stem tool helps to fish but you still have to fight to get the valve at 90 degrees to the rim hole to feed it through.
Anyone else have a good secret?
I am going to use Zip-Ties from now on. I used a small screwdriver to lift the lock tab to release the zippies for reuse.
I picked up a bag of 15 (?) at Lowe's and now I keep them in my tool box with my tire tools.
Hope this helps