I do home childcare and in the last year or so, thanks to a fantastic former client, am a big supporter and fan of the "3 day potty training method" by Lora Jensen. I have had parents do this method, then I continue it here at daycare, with all of my full time kids , with 100% success in this time frame. The youngest a 22 mos old girl..the rest were all boys..the oldest was the first one and he was 28 mos old. My most recent did it over the weekend of his 2nd birthday. Some take a few more days for it to be truly a cemented idea and working system...parents should not be discouraged by this. And poo'ing can be longer. No biggie..especially if you are working toward the goal. Figuring out some modifications, after the initial "training" are understandable! (such as PU or diapers at night for a spell or similar. I think most of mine did after an initial attempt for a few weeks..then phased them back out quickly).
But for daytime, naps and such...nothing but undies here with me for the 8-10 hours a day. And I never ever once make them go sit at timed intervals or tell them its time to go potty. I do remind frequently, at first, that they need to tell me when they need to go potty...make sure you let me know when you need to go potty....remember I can help you when you need to go potty......there is a subtle, yet distinct difference. I don't make them go. They TELL ME when they need ot go. Every single time.
I also do a single M&M with a successful pee or poo. Never get one for just trying, only for a success. Boys generally sit facing backwards...the front of the seat offers support for their bum so they don't feel as if they are falling in the potty and for most boys, puts their hips in a good position to aim, without really having to aim, ya know? Wearing just undies and shirt (no pants) is critical to success the first few days or weeks...need to be able to respond FAST when they say they have to go! Obviously this for at home and if in a home daycare, if your provider is on board. Ease into loose pants such as sweats/athletic pants. Jeans are hard. Expect accidents and you need to be able to que into even the most subtle signs..before they become verbal about telling you. My first little dude whimpered..then almost cried...then we figured it out about 2 weeks later he was easily telling us. He was learning what his body was telling him, so he could communicate that to us (his various caregivers..parents and me..occcasional evening sitter/grandparent).
It works! 2 years can easily be trained. Its a battle...but in the end you win the war and reap the benefits. Years ago, most kids were trained by 2 or 2.5 years old. now thats a whole year later. Who wants to change the diaper of a big 3 + year old? As a provider of many many years...my days of that are over.
Best of luck to you! You can do it..and so can your child!!