Stalker420,
As with every technique, use common sense and start slow. I find using a simple sneaker shoelace and tying it to my knee (alternating each side to evenly distribute the tension) gives a comfortable and concealed stretch--the bonus here also is you can add more tension by simply stretching your knees (opening your legs to the side to increase the tension) while you sit down doing whatever you like.
You will find that it hurts a bit as you roll the condom-like tube (the smaller the tighter the grip--I use a yellow hi-lighter, for example) over the glans. Once you roll the tube over your glans, however, it will be comfortable. After about 30-60 minutes of stretching, you will feel heightened sensitivity and it will be wise to remove the swim cap. This part will be the real pain because of the heightened sensitivity. The latex material will adhere to the glans and skin so you will have to SLOWLY unwrap the swim cap and even more slowly peel the swim cap off of your glans. This sensitivity only lasts a few minutes--easily cured by massaging the area. The beauty of this technique is you don't have to worry about any blisters (grrrr!), poor circulation, blood spots, or whatever.
If you are uncircumcised, I would recommend using a Theraband sports wrap and do a light wrap where your foreskin is pull back.
As a side note, foreskin is very annoying. I know because I was uncircumcised for 26 years and just recently got circumcised. The sex is much better and cosmetically it is much better looking. I can understand why some may want foreskin restoration, but speaking from someone who knows both sides of the coin--a circumcised penis is much better. I would highly recommend it for those considering it, regardless of age.