Well done J!! We have a similar fusspot eater and drinker - 16.5 months milk out of a bottle or me, nothing else, sippy cup was tried for a month until he got poorly and completely refused and I just gave up
.
I think I have been doing it wrong as I've been introducing his cow's milk in his beaker (was hoping to tackle two things at once), with breakfast and lunch. Lucky if I get a sip out of him. In fact I've been really pleased with sips - clapping and cheering like a crazy person. The rest is dribbled, spat out, flung, tipped... sigh.
Think I might try your version and just give it 3 weeks, one ounce at a time, in his bottle and get that tackled before moving onto the beaker. He'll drink his juice out of beaker perfectly fine but gets quite upset when milk appears in it.
Thank you - I now have a plan!