Recovery

[Import]

I find that when I train a muscle group when it is still quite sore, it is not sore the next day. Why is this?
The other day I had extremely sore biceps and had another back and Bis training coming up so against all good advice I trained them anyway. I trained them very hard so I thought that theyd be twice as sore the next day but to my surprise there was no DOMS. Did I help my muscles recover by doing this OR did I just get my body to ignore the pain.
I am thinking of using this phenomenon to facilitate better recovery. A couple of light sets to remove DOMS on days when I am not training that muscle group. Maybe even Just doing my usual warmup for those muscle groups. So the training could be like this
Day1 Chest Shoulders Triceps heavy and Back Bis legs a couple of light sets to facilitate recovery
Day 2 off
Day 3 Back Biceps Legs Heavy Chest shoulder trcipes a couple of light sets to facilitate recovery
Repeat

Heavy might be the wrong term Hard might be a better term as I don’t always go “heavy”

Will this damage my muscles or is it a way of enhancing recovery?
What is the physiological mechanism behind this?

[Import]

I have read some info on this subject before. I am not sure if it was Paul Chek or Charles Stanley that spoke of this. Anyhow the idea is to do some light sets(feeder sets they are called) for muscles that are still recovering from a previous workout. This is supposed to help with recovery by getting the blood flowing to those muscles. I have not tried this myself so I cannot tell you what to expect. I wonder if this can be used all the time or if it should only be used during specific phases of traning?