“How does one pick the proper placement for a Guiche? Should one plan on wearing a cock ring (if that’s normal for that person)? Should Guiche placement be behind where the cock ring and is the Guiche comfortable to wear daily (never remove it)?”
A Guiche is considered to be a genital piercing, and is placed on the perineum between the anus and the scrotum. Sometimes on or very near the base of the scrotum, sometimes it is located closer to the anus. It often provides additional testicular or prostate stimulation for a man during sexual encounters. It is sometimes performed on females, but that practice is rare.
You should select the proper placement for your Guiche in consultation with your piercing professional. If you plan on wearing a cock ring with your Guiche, please let your piercer know. You may wish to bring your cock ring with you to get your piercing, so that your piercer can see what it looks like and plan accordingly. Remember that this person is a) a professional at their job b) performing a medical procedure on you and c) has heard of just about everything that you can imagine in regards to piercings and body modifications. Withholding information out of embarrassment that your piercer is judging you is one of the most foolhardy things you can do. Think about it, you are trusting this person to make a permanent (or semi-permanent) modification to your body, you should be able to talk to them about what the body modification means to you. Trust me, if they are about to modify your genitals in some way, they will assume that there is some sort of sexual component to what they are about to do, so you lose nothing by being honest.
I don’t have a Guiche, so I don’t know how comfortable it is to wear, but the research I’ve done suggests that you should leave it in at all times, or you risk having the piercing close on you. This is at the very least true during healing, and your piercer can advise you on keeping it clean and healthy while it heals. If you sit a lot at work, it may be uncomfortable for a while, but your body will eventually adjust.(PS. The advice above in regards to talking to your medical professionals, and being honest, is true for ALL your medical professionals. If you are uncomfortable telling your medical professionals the truth about yourself, get a new professional, or a new lifestyle.)