This is a great topic. In Feb 2006, I used the TSP Loan to pay off my credit card debt. I didn't have any house to use as equity. At the time, my credit card kept hovering around $4,000. I'd make some nice chunks in it, but something would happen - like getting a car inspection and ending up with a huge bill at the end of the day.
I took out a $10,000 loan, paid off the card, and planned to use the rest for my wife getting a start on being a self-employed artist. A few months later, my car was stolen. So the rest of the money went to buying a used car. At least I did not go into any extra debt! I finished paying off the loan this January. By that time, I had gotten so used to getting by without that money, that it immediately went into my savings account every paycheck. That was great, because then I was offered a promotion which would involve a move. So in those few months, I was able to really build up some extra money in savings for the down payment on a house.
All this to say that I am so happy to not be using a credit card any more. I consider regular savings deposits a bill that I MUST pay. My wife and I have been able to manage our money without using credit cards for two years and we've consistently put away savings - and that is with just
one income. She doesn't get paid except maybe some random check for three hundred dollars after two months or something. So, we're able to provide for ourselves, our kids, and make payments on a $280k house on just my income - and I don't make 6 figures. My pay is well under $100k.
A coworker of mine has consistently been making $20-$30k more than me, plus his wife worked, and they were drowning in credit card debt. It eventually became one of the factors that led to their divorce. Some people say that you shouldn't touch the TSP, but if that's what needs to be done, go for it - it could save a dying marriage. You'll never find a loan at a better rate. It takes discipline, but living without a credit card can be done.