Just because it is sticky doesn't mean it wasn't purged correctly. Have you tried PureGold? It comes in liquid form because all of the parrifins have been removed. Also making BHO is just like making candy, you need spcific temps for specific results. If you over heat your oil it comes out like shatter, if you keep the temps low during purge you get budder/wax. I make quite a bit of oil and this is just my experience.
Also, if ya want to make sure your oil was puged properly just drop a small chunk on a hot nail and see if it sizzles and pops,or if it leaves a residue on the nail, if it does then it wasn't purged properly.