Apples,
The way you describe it sounds like the typical Aussie solution - where a length of wood, some string and some bubble gum are applied successfully no matter the extent of the problem...
However, the method you describe is pretty much how many professional bodywork companies roll fender lips as well.
In my opinion, especially members in colder locations will want to avoid painting chipping / flaking at all costs to avoid any future rust problems.
Some slight variations, which may help to avoid paint chipping/flaking is to spread the pressure you put on the fender lip a bit by putting some thick cloth between the wood and fender lip. Also, using a round piece of wood or metal and actually rolling it between the tire and fender lip will help. Lastly, not bending the fender lip in 1 go, but in gradual steps should help.
/Kees