For exercising I wear a size tighter in girth and/or a size shorter in length so that retraction does not occur.
The Corkscrew will be quite obvious in your regular fitting pants. I will use mine mostly at home and for short outings in which I anticipate moderate activities and causal interactions. I wear an untucked shirt for complete privacy and occasionally without if I don’t mind drawing some attention 😉
You can also shorten the coil with a box cutter and use the PVC end cap that is included with the kit to seal. Experiment by removing one coil at a time until you find your preferred length. This will make for a lighter/smaller profile Corkscrew that is easier to put on to wear and conceal under loose clothing.