For years I would insert a hard plastic cup with rubber edges by itself into a XL jock. I often had trouble inserting and removing the cup while wearing the jock at the same time. I found myself "scratching" in public more often than others and for longer periods of time. I also felt the cup chaffing up my underside when worn over longer periods of time. Now that was an embarassing situation for this XXL old man.
Now I have discovered an easier solution to these problems. First place the cup into an old leftover jock and cut off the leg straps and waistband. Whala, now the cup will slide easily into and out of its correct position in a new jock. No more trouble with quick cup adjustments and far fewer needs to check its position in view of the ladies. The chaffing issue is also addressed. Please check this out for yourself and pass the info along to others. I use to ruin the leg straps on older $7 jocks much too often. Now I even save money because their lifetime usage has lasted much longer than normal.