a few of the methods mentioned should be helpful as I would imagine this is primarily for their benefit..

I was just a young'n when I noticed the grandparents liked to pay largely by credit, and since I knew of my folks getting free travel through mileage ccs, I persuaded them to also get the same "card's that'll get you free trips for what you already spend"...Needless to say they seem to specifically enjoy putting things on credit and having a free trip here n there...also been kind enough to throw some my way once in a while..

If that's the intention, why not help em out? As mentioned, even with no credit getting secured cards shouldn't be an issue... often you can even secure them with a gic or other interest earning investment instead of just putting up cash