Purify and punish are not identical. We seek purification. We do not seek punishment.
Punishment doesn't occur in that post anywhere.
And we are purified in the crucible of Christ who burns the dross of of our lives HERE while we are alive so we can be able to stand before Him on the Day of Judgement, He can then proclaim, ‘Well done, thou Good and Faithful Servant. Go to your reward.’ And it’s not purgatory.