Great for a field bag.
Let's get it out of the way - yes, you can just use Isopropyl, it will work just fine. However, I love these because they are AWESOME to have in my call bag. The bottles aren't overly large, so they don't chew up a lot of space in the bag, and because of the tip, it's also highly unlikely that they'll make a mess - catastrophic damage/failure not withstanding, but that should be a given. Adding to that, generally speaking, you only need but a few drops, so even their diminutive size isn't a concern, as it will last you a while. Even in worst-case situations (baked on TIM on a 360, 10 year old, dried out past on an XP box that just. won't. die.) it still doesn't require very much to do the job.
Rating: 5 stars