You could use your cone five glazes on your cone 10 clay, and most likely you will not have crazing or crawling issues. The main thing to be aware of is that your cone 10 clay will not be fully vitrified, meaning it will remain somewhat porous. So it will be less functional. What kind of clay work do you? If you make sculpture or decorative vases or something like that, I wouldn't think twice in using the cone 5 glazes on cone 10 clay. If you make dishes your want to use, I would get cone 10 glaze and fire to cone 10. What do you plan on making?