When they say 'petrol' they cannot be referring to the stuff that you put in cars. When it burns in air it is smokey and potentially explosive.
Petrol is a generic term often used to describe low flashpoint hydrocarbon mixtures. You often hear people refer to Coleman 'white gas' (/'Coleman Fuel') and BBQ lighter fluid ('naptha') as petrol. My guess is that when performers talk about 'petrol' they mean 'naptha' and therefore 'Coleman Fuel'.
You even get it applied to high flashpoint mixtures sometimes (Vaseline is almost universally referred to as petroleum jelly).
Paraffin is also a mixture of hydrocarbons (usually mostly alkanes). No two batches are ever exactly the same but they are mixed to have extremely similar properties.
In some countries (USA mainly) Paraffin is called Kerosene. Be very careful with this label though as most countries in Europe use this to label a specific mixture that us used as jet fuel.
(Think of naptha as being similar to petrol and paraffin as similar to diesel although this is not a great analogy)
Lamp oil is often a specially filtered paraffin with additives to make it less smokey (this is usually not great for spinning as some smoke is needed to see the flames on fast moving wicks).
For what you are describing I think you want to custom mix some naptha (Coleman maybe) and paraffin. The paraffin on its own is too viscous and unwilling to light for body flames but the Coleman fuel burns too hot and too quick on wicks (I've been told you can do contact and body flames with tiny amounts but I've never tried it myself - so be very careful if you are going to! - speak to whoever is teaching you before thinking about it!!!). I'd suggest mixing up some samples (starting with a few drops of white gas in paraffin and slowly adding more with each sample) and testing them on something that is not your skin (maybe a bit of old leather?) as well as a small piece of wick (use a new piece of wick for each test). That way you can have complete control over the burn characteristics.
You really should be aware of the dangers associated with each fuel too. I'd start with Wikipedia. Coleman Fuel is a naptha: http://en.wikipedia.org/wiki/Naphtha
and is potentially toxic.
will give you dermatitis is you get it on your skin too often (and you can never really be sure what is in it).
There's loads of info online (and specifically, on here) about that though.
So you know what you are looking for...
Coleman Fuel: http://en.wikipedia.org/wiki/Coleman_fuelhttps://mycotopia.net/forums/attachments...an_fuel_500.jpg
If you are ever unsure - don't try it until you've spoken to someone that knows what they are doing!
And, definitely don't ever use the stuff that is made for cars.
Except in a car of course.