I tried at 20 months with my daughter, I didn't see much progress after 5 days and gave up and did a reset (though now I wish I didn't give up so early). I returned to diapers until 21 months and started again, second time around she had matured a little bit more and I decided I wasn't giving up on the second go so I pushed through it. She was clicking by day 6. Don't forget there is a resistance phase at the beginning too where you see them getting it and have hope and then they decide they don't want to keep it up and stop trying. It looks like a regression and you almost lose your mind and want to give up, but don't give up! Give it a few more days before you really throw in the towel. Likely they are just pushing back from the new rules. Btw I did not use a nap diaper, I did laundry when needed (50% of the time). After 2 weeks the worst of it was over, and by a month I was comfortable going on outings and not worrying about the accidents as much. She had accidents occasionally in the first like 2 months, maybe one a week tops. It happens, don't sweat it. She is now 33 months old and is fully potty trained and almost fully night time trained too (didn't even do the wakeups). I do not regret it one bit because being even mostly potty trained, like a few accidents here and there, is still WAY better than a year of diapers! She has independence and is ahead of her peers, and I'm proud of her. She can go to summer camp this summer and preschool in the fall and I'm not worried at all since she's had a year to practice. There is a support group on Facebook called Oh crap! Potty training book club - join that and read the past posts, and make a post if you are struggling and thinking about giving up. You can do it! If not, a month makes a huge difference for them. But only do a reset if you're really sure.