good question. You gonna have trouble with that frozen juice. already you have a chance of it being cloudy to start, heating it will cause pectins to form and you definatly have it being cloudy then... I may hate camp tabs for a number of reasons but i have to agree with Tusch... not to say you couldnt heat it and pastureized it will cause problems... you might try home UV pasturization, i have had sucess with that, retro fitted an old UV gogle station to hold two 3 gallon pails of juice, by taking our the shelves. I have heard the same works for putting your juice in bottles and running a UV light into the bottom of a 5 gallon bucket then putting the bucket over one bottle at a time for 30-60 minutes. but you need a rather stong wave UV bulb. The cabinet works for me like a charm. But with lack of a UV setup... camp tabs or another chemical is your best bet.
Cheers