Yep, after almost pressing the buy button on a compressor from Screwfix after years of the straight up/no chance lottery and struggling with a pair of Rocket Rons today I tried this as a last resort. I've run tubeless for years and have always got them on eventually but fed up with struggling at times.
Took about 10 minutes to make. Used two prestas one with the core and one without and a short bit of tube from a previous tubeless kit. Mole grips to kink and hold the the tube. Pumped up to 60 psi with a track pump, let off mole grips and hey presto it worked first time on a tyre I had been struggling with for an hour. Absolutely brilliant and still have power in my arms!!