I use a high temperature silicone rubber soldering helper from Austin Ribbon Mics to support my soldering.
However, I’ve read some comments that people would like to use this, but A.R.M. does not ship to their country.

Well, how about making one? I bought some silicone rubber from Amazon and built my own.

Pretty simple, pretty messy, and in the end pretty useful.
If you can’t buy one, or if you just want to make a custom one for yourself, here’s the process.
(Making it)[]