DD is just a bit older and we are doing pt as much as possible. Around the house she is in gerber trainers or straight up undies - as long as we are on the main level w/o carpets lol. Out and about i will put her in a TTT trainer with pul-backed soaker which will pretty much hold one pee. I find that the wetter she feels - and esp if she can see it, undies dont hold anything - the faster she "gets" it.
Eta if she is in a gerber trainer i will sometimes just put an empty pocket dipe over it fir a quick trip out.