It is possible that the "local Artisan" does use a regulator, but that the regulator does not look like a typical regulator with a gauge on it. For example, I use an EZ torch with propane. The regulator on my torch setup is hard to identify as a regulator as it does not have a gauge on it. If you follow this link, you can see what the EZ torch regulator looks like.
You mentioned that maybe the propane pressure in Jeddah is lower than the UK. Unlike oxygen and other compressed gases, propane stored in a tank is actually liquid with a vapour space above it. As you use your torch, the propane liquid actually evaporates to supply propane to your torch. The pressure of propane is fixed by the temperature it is stored at. At 80 (27C), the pressure is 128 psig, at 90F (30C) 149 psig.
Also, many warmer countries tend to use Butane rather than propane. I lived in Malaysia for a year, and our gas was supplied by butane tanks. I was also recently in Morocco and they had no propane, only butane. As a point of comparison, the pressure of butane at 80F is 23 psig. This is substantially lower than propane at the same temperature. I am not sure that you could get away with no regulator, even at this pressure.
Also, @janetb mentions that in Israel they use a propane/butane mixture. Generally all of the propane available in the UK and Canada and the USA has butane in it and conversely all of the butane available in warmer countries has propane in it. This has to do with the process used to produce these gases. Making pure gas is possible but not practical (ie uneconomic) hence the gases sold all have some contamination from other gases.
(Note that I am a chemical engineer and used to design the equipment used to make hydrocarbon gasses, including propane and butane)
I don't know why your torches are gunking up. I have been propane for many years and have never had this issue.