Sealing Cheese Shakers

I'm having a problem preventing people from opening these glass cheese shakers: http://www.globalindustrial.com/p/foodservice/pizza-supplies/pizza-stands-risers/12-oz-fluted-cheese-shaker?infoParam.campaignId=T9F&gclid=CMSFh52QoL4CFRFk7Aodb24Aug&gclsrc=aw.ds I don't want customers opening them up, what can I do create such a seal that it would be extremely tough to get open, and that when I take them back, I can open them to refill them? I can’t tighten them hard enough. Thanks in advance.
- cesar (age 29)
Houston Texas USA

Wow, this question is a nice change from the ones about quantum fluctuations and the Big Bang. Here's a possible thought. Maybe some nice non-toxic edible wax (paraffin) could be used in the threads. You'd heat it up to seal the shakers and to unseal them. One possible drawback might be that it would take some care to heat it without damaging the grated cheese inside, in case you want to refill before the shaker is completely empty. Probably you want to get food-grade paraffin with the lowest melting temperature you can find. Maybe also a little electric heat gun for heating the lids without heating the glass much would help.

Maybe some of our readers will have better ideas.

Mike W. 

(published on 05/09/2014)