Not sure that this is technically an exploit, since it's a UI mod doing the work, but it is a really helpful trick.
You'll need the UI mod, Outfitter, which is an incredibly useful add-on that allows you to set up outfits that you can switch to at the click of a button. It also has settings to allow the mod to automatically switch outfits based on circumstances. For example, automatically equipping your riding crop when you mount up.
This UI mod also has a setting for "Rogue - stealthed". I think you can see where this is going.
Get a nice slow dagger with a high top-end damage and use the mod to equip it while stealthed. Now you can use ambush, then your mod will automatically switch you to your swords/maces/fist weapons so you can continue to use higher dps spec's while still getting that huge burst dmg to start off.