Having just done a trip round half of Oz with 4 R 22/44s can relate our experiences.
We had quite a few cold mornings with difficulty to start.
We had a can of "Aerostart". Actually we a can of its generic equivalent "Start-ya-bastard". It is an aerosol can of some sort of highly flammable stuff. As you can see I really know what I am talking about too
I had never seen it before but the guys I was with have used it on previous trips. So I watched them use it first and got them to do the spraying while I turned over the engine. Started quick every time except one - Tamworth -with ice on the bubble covers. The battery ran flat so we had to jump start it from a four wheel drive.
Now I am told there is a risk of doing bad things to your engine so I take no responsibility if you try it and and if it happens. I think the problem can arise from spraying too much but exactly what it can do I don't know.
What you do is:
Get a rag folded into a wad. Need one person on the controls and one on the spray can. Place the wad over a bit more than half or so of the air intake opening. Hold the can ready and when the ignition is turned on spray short bursts of spray into the air intake. Most times it fired up on first or second turn.
I would recommend asking around and finding someone who has used it and really knows what they are doing. I was just a grateful bystander - so-to-speak. But at least you know the stuff exists.