I'm not sure. I've never bothered re-gilding, mostly because it feels like a waste of hero souls.
The best way to expedite your speed that I've found, is to just keep playing. Focus on getting useful ancients and leveling them up. Vaagur is pretty much a given, at max level he reduces your skill cooldowns by 75%, which means you can use Dark Ritual every hour. It's a slow way to increase your damage, but it does help.
Also, depending on your playstyle, certain ancients may come in handy. I mostly play as an idle build, so my ancients mostly help that. Siyalatas for bonus dps when idle, Libertas for bonus gold when idle. Bubos for reduced boss health (max level is a 50% reduction). Dogcog (50% reduced hero hire/levelup costs at max level). I also use Atman for extra primal souls, and Mammon/Dora/Mimzee for more gold and treasure chests.
Double also, make use of the mercenary function. I've often found that sending them out for gold has gotten me to the point I can throw a couple hundred levels onto my strongest hero, enabling me to break the wall I've been stuck on easily.
Another thing to consider are rubies. Though a premium currency, you can obtain them relatively easily through the clickable drops, as well as mercenary quests. I'd recommend saving up for 50 and buying the hero souls/ascension item. It's pretty lucrative.