I think it sounds cool! It really depends on the couple though imo. Am going to sound really snooty now...
If MrMG and I had done that, our friends would have taken it as intended - a bit of fun, and an interesting display of - owlry? (like falconry...) If you do it because you think it's 'romantic', hmmm...
Actually, may I propose a test?
The crapping... if you could laugh during the ceremony and it would become a favourite wedding day anecdote if you were crapped on - then it isn't twee and awful to have it. If you would cry and your day would be ruined... then you're a bridezilla who needs to get over themselves, and it's OK for people to laugh at your twee owl plans. 