Yeah, it will work, assuming that it is actually glucose. Or you could use glucose powder (£1.50 for a pound at Boots). The main selling point of HypoStop/Glucojuice/Glucotabs, however, is convenience - how are you going to transport the liquid glucose (since it's for baking, it will be a lot more than the 15g you would need to treat a hypo). How long are measured applications going to keep (you shouldn't be having hypos frequently enough for this not to be an issue).
You don't particularly have to use HypoStop - your pharmacy should be able to order some Glucotabs if they don't stock them. Or maybe try some of the glucose gels marketed at runners.
Edit to add: Keep in mind that glucose dissolved in water only doesn't taste particularly nice either.