Compartmentalizing can be a healthy adaptation to managing stress, when it is essential to do so. Compartmentalizing is putting things in boxes so you can go from one box to the other and not drag things between. It can be a critical survival skill. Go ahead and google "healthy compartmentalizing" and see what others have written on the subject.
Compartmentalizing can be unhealthy if you never deal with the trauma you put in one of the boxes -- if you never consciously go back into the box, but what is in the box is still there and eats at you subconsciously. If you develop anxiety, have nightmares, choose alcohol or drugs to mask feelings that eat at you in the background, have trouble with angry outbursts or are prone to crying jags, if you feel disconnected from the world, etc.
Compartmentalizing can be unhealthy if it's YOUR OWN awful behavior you stuff in a box and don't think about as well. Psychopaths can be skilled at compartmentalizing to the detriment of everyone around them.
Stuffing things in a box and pretending the box doesn't exist, or that what's in the box isn't bad, yes, that is not healthy. When what is in the box you are pretending doesn't exist is another person's awful behavior, well then that is the definition of rugsweeping.
Rugsweeping is an unhealthy adaptation to managing stress, because it denies or minimizes the awfulness. It lets others off the hook and allows the awfulness to persist, it pretends, it distorts, it denies.
Choosing alternate thoughts, deliberately, as a way to escape recurring thoughts or emotions that hijack your brain is NOT RUGSWEEPING. It doesn't try to reframe the awful thing that other person did and morph it into something not-awful. It doesn't deny the awfulness! That's because it doesn't have anything to do with that awful thing that person did. It just puts that awful thing aside, and says "not now". It doesn't mean "not ever".
Meditating is also not rugsweeping. If you can sit and focus on your breath for 15 minutes, great. I can't. I've tried. It doesn't work for me. My brain wants to be attached to a thought, it wants to be engaged. My brain is overactive. It is constantly searching for connections, to link two thoughts, or three, or four. It can get really old when you play the same sequence over and over and over in your head, and the sequence is AWFUL.
So rather than fight myself and my own brain when I'm in pain, I give my brain something positive to work on, I give it healthy pathways to go down. In that way I get some relief from the awfulness, when the real, genuine, world-destroying reality I'm living in is not something I can cope with 24-7. I have to turn my brain away from the terrible loop it's in with the chronic replay of the movie I've seen 100 times.
Please respect that there are a number of ways of coping with the trauma of infidelity. If this tool doesn't work for you, that's OK. But try not to disparage it or mischaracterize it as something dysfunctional when it is a healthy tool for others.
FBW then 46, XWHNPDPAFTG the destroyer of my entire life. D-Day 1 '99, D-Day 2,3,4,5,6... '09-'11, D '15. I fell apart. I put myself back together. Forgiveness isn't required. I'm happy and healthy now, and MY new life is good.