Like re-used pickle jars, your bottles will probably retain the smell of fixer. Also, I've found that silver tends to plate the glass after a while, which you might not see if the layer's very thin. You'd be better off to buy more beer in glass bottles and use those; besides you can have more fun with the contents! :-)
last week when it was suggested to keep photochemistry out of the reach of children because developer and fixer were harmful to one's health ...
... it seemed "kooky" ---- "children were being protected" = "nanny state" &c
now ... when an adult asks if it is ok to reuse fixer-jars for beer
it is OK to say that photochemistry is harmful to one's health ??
Chemicals that may contact the skin are one thing, but those that might be ingested are another. Even in trace amounts, you should NOT take any chance of ingesting photographic chemicals. Silver metal and silver salts are used as topical bacteriocides, but are poison if swallowed.
This is a supremely unwise idea.
Do not use any cooking utensil for holding photochemicals either. Do not use a cooking pot or measuring cup for chemistry that might ever be used for food!