D&D 3.5e weapen enchant speed?

Unfortunately no it will not work that way. While it is hard to get the max effect from a double weapon I do not share the opinion of Fire that they are not worth it. As a two weapon fighter there is some positives to using a double weapon, but if you can get a enchanted main and enchanted light offhand weapon then it would be best to use those two over a enchanted double weapon.