Great idea, and I hope it works!
Do arrange a NOTAM, though, and please please please don't do what lots of balloons sites to: get a perpetual NOTAM saying "we launch baloons sometime, go to our web site or phone this number for launch times".
It's not fair to expect every flyer to have to check every balloon web site (there are lots of them) for launch times - update the NOTAM regularly with specific launch dates/times if you're repeating the launch.
I don't want to put you off - go for it - but give specific dates and times (even if approximate) in the NOTAM please.