When my oldest was heading down the slacker path, I booted him out. The rule is: to stay at home after age 18, my kids must either be employed full-time or in school full-time and passing.
My son ran out of money and enlisted in the Marine Corps where he is thriving. He went in as a PFC because of the college credits he got during high school (we homeschooled and he went directly to community college and bypassed high school). He became a Lance Corporal in less than a year. He is ambitious now and working hard for his next rank. His MOS (Military Occupational Specialty) is so difficult that he will train for over two years before he is certified. His high test scores made this possible and he is training in Meteorology/Oceanography forecasting or, in other words, to be a weatherman. Weathermen are embedded anywhere aircraft land.
Kicking him out was extremely difficult, but it was the right thing to do. It is not slacker men who are the problem as much as slacker parents who don't have the guts to do the hard thing. They don't have the faith in their children to know they can make it on their own. My son said I made boot camp easier because the DIs (drill instructors) had nothing on me for being tough. He has already thanked me several times for kicking him out and being tough and he is only 21. He is also stunningly handsome and I could not be more proud.