I'm also in the camp of less is more. Because I can rattle off in spanish without a thick accent, they'll often come back at me with something I can't understand. But that helps grow my spanish and enriches the experience.
?De donde viene usted? Answer: California
?A donde va usted? A pescar en Gonzaga.
Anything beyond that may just lead to confusion, and possible offending the guy with the big gun. Whatever you do, under no circumstances should you ever use the word mother (madre) in Spanish to someone you don't know very well.
If you want to practice your Spanish, probably better to pick someone other than military personnel
