The mouth swab is something I had never heard about. Back when I was put on the list, I had to go to the Red Cross apheresis department and they drew blood samples.
That led to about 120 units of platelets over the next many years. Unfortunately my schedule changed, and I haven't been able to donate platelets in several years.
Often, if you watch the local news or read the papers, they will have a local drive to enroll people. This is often paid for by a fund honoring a sick or deceased patient who needed the transplant.
Forget the time commitment thing, just enroll if you have the chance. You or a family member might be in need someday and you would sure have a different perspective then. Good thread.