u/Dry-Buy-8241

i just got a clay graphite crucible and i see that you have to temper your crucible and i see that people say to put it the oven for a hour at like 3 to 400 degrees and then let it cool and then to put it into your forge and slowly raise the heat but im using a charcoal/ fire powered forge what would be the best way to slowly raise the heat? or is there a better way to temper a crucible?