We did exactly that when I was with Derbyshire beekeepers about 6 years ago. 2 samples failed out of 14 and one had been bought-in by an old lady who's crop had failed and the other was a commercial one in a dark jar and sold as active honey. Actually a third one failed but it was one that I had deliberately overheated to show people how a spoilt sample came out (I had expected every sample to pass). The lady with the bad sample was very embarrassed although we all tried not to rib her so you have to tread carefully.

I forgot to add that the water/honey proportions are by weight.

I got my second and subsequent tubes of strips from RS and paid about twice what I paid for my first ones but my original supplier refused to sell me more in retail quantities. I think I would have had to buy around 1000 strips instead of my usual 50. RS strips measure up to 100ppm but 25ppm strips would be more appropriate. Unfortunately I have never found 25ppm strips in this country.