Struggling to move from 'Sabaidee' to actual conversation with my Lao in-laws

I’m a heritage learner, and while I understand most of what my grandparents say, I freeze when I try to reply. I keep falling back on formal Thai-influenced vocabulary, which makes them laugh. I need a way to practice speaking naturally without the pressure of a family dinner; has anyone used Chickytutor.com to simulate casual conversations or get corrected on 'Lao-proper' colloquialisms before I see them next?