"I feel like I accomplished everything I came out here to do," he said. "I feel like I've learned a lot about myself and I got to learn how to dance and dance with Kym (Johnson) so it's been really amazing."
Arquette and his partner, Johnson, ended up in fifth place Monday with 47 points out of 60.
Arquette said the show has helped him get in touch with his body and his mind. He's been sober for 10 months and now feels stronger.
"This was just something to keep my life on track and in general just do things that are positive, that challenge me, that help me learn more about myself," he said.
Johnson has learned a lot about Arquette, too.
"He brings so much heart and soul to this group," she said. "Everyone does love having David around all the time and he's just a great energy in the room always."
Arquette finished three points ahead of last-place dancer Nancy Grace, who relied on her fans' votes.
With Arquette out, the five remaining stars - Grace, Ricki Lake, J.R. Martinez, Rob Kardashian and Hope Solo - continue to fight for a spot in the finals.
"We have to put in more time," said Cheryl Burke, Kardashian's partner. "Now it's really getting close. Now you have no idea who's going to go home and you have to make sure that every single dance you do, you do well."
"For me, at least, it really steps up and now it becomes intense," Martinez said.
Justin Bieber also appeared on Tuesday's episode, where he performed his song "Never Say Never" and unveiled a track from his new Christmas album, "Under the Mistletoe." The teen star sang "Fa La La" with Boyz II Men.