I'm not sure what you mean by "burn to the point it's unusable pretty quick" You can use a wet sponge or towel to clean the crud off the iron while it's hot.
Not sure if you know this or not, but don't use acid core solder or acid flux either(used for plumbing), rosin core is what you want to use for electronics.
every review for this iron said the tip doesn't last long at all. one said a couple hours at most before it needs replacing
yup, I icked up some rosin core solder too