An Offer in Compromise does allow you to settle your tax debts for less than you owe, and they are not that difficult to apply for. The main trick is that you have to document ALL your assets, liability and income, to prove that you are unable to pay the full amount. It is a lot of work, but not overly complicated. There are a few other ways to qualify, such as if there is doubt as to what you owe, but these are again best handled using a local CPA or Enrolled Agent (EA).
The VERY FIRST thing you should do if you have large tax debts and think an OIC is for you is to use the IRS' handy tool for seeing if you qualify - https://irs.treasury.gov/oic_pre_qualifier/. Chances are, if you have a lot of equity in your home, money in the bank, or a well funded retirement account, you aren't going to qualify unless there is serious question as to whether the amount you owe is accurate, or you have some specific hardship that makes it reasonable to compromise. Talk to a local CPA or EA and explain your situation. Most will advise you for free or at a low cost as to whether you might qualify, and, if you do, help you prepare an offer for a few hundred dollars.
Check out the rest of the "Dirty Dozen" here: https://www.irs.gov/newsroom/irs-dirty-dozen-list-warns-people-to-watch-out-for-tax-related-scams-involving-fake-charities-ghost-preparers-and-other-schemes#oic-mills