A lightbulb does work, but i don't think it would be a great idea since the lightbulb has some disadvantages, like getting hot and it requires more power to light the bulb, so, you need better batteries (like 2 AA or something like that, instead or just some wristwatch batteries that cost a little and lasts a lot in a LED).
Using hotglue works great and is a better choice, it widespreads the IR light so it can be visible from a wider angle (not a lot BTW) but any improve is always good.