There were tricks we all used for traction devices in the past and even now.
The first has always been retracting your foreskin completely back to allow the sleeve and bandage, or even the foam collar, to bind to pure unmovable skin area. However, when your penis keeps on shrinking because of sensitivity, the looseness causes the slippage.
Which comes to the second portion of the game plan. In the old days, we use Ace sport bandages, which was great for traction, but holy smokes, it get uncomfortable after a while. Ripping the skin off because of adhesive was even worse. Now, we use Theraband and similar flexible soft materials to wrap. The TheraBand around the base of the penis helps to create powerful traction on top of using the penis corona as a stop end for movement. Even when your penis shrinks, the TheraBand grips onto your skin further.
Third, we use a mix of magnesium carbonate with a bit natural rosin. This is MOS Grip Powder. It pairs up with the TheraBand to safely bind the skin to the soft materials without being a glue. The higher the rosin percentage, the stickier it gets when you build up moisture. It's what the pro athletes use for grip strength. Just be careful not to exceed 20% rosin or you will have one sticky penis at the end of the day. Having sex while the rosin still on the skin will cause some massive painful traction for your lady friend. But I can say it feels like one tight pussy for the first 5 minutes. After that, friction city baby.