I just take a larger screwdriver, when they are new, and pry the clip open a bit til they slide off the sling keeper.
When you have them in place and tension on them, they will not come off, but when you WANT it off, it will slide off with minimal effort.
If you dont have an extra clip, take the sling clip off the backside, and re-assemble the sling with the clip on the front. arrange the sling where the clamp is facing towards you (backwards) when installed. That way if you need to adjust it while in place, you just reach up, pull on the end of the sling, which unlocks the clamp. Adjust to length, and reclamp with the same hand.
When you reach a cease fire, you just unclip from the front sling swivel, and leave the sling hanging on your arm. I set the clip up so it clips back on from underneath (clip up).
Of course, if you have an extra sling clip, you can just add it to the front of the sling...
I think I'm following what you're saying, but some pics would help. I'm gonna mess with mine and see what I can come up with.
http://www.ray-vin.com/frtech.htm