I found this question and answer on the rethinking hell forum, and I agree with Chris Date's answer:

Balletbug:
I am almost convinced of the conditionalist view of Hell, and find it a relief as I was struggling with how a God of Love could torment souls with indescribable pain for all eternity without end. I have just read the book 'Hell, A Final Word', by Edward Fudge, which has been very enlightening. However, I am struggling with Revelation 14:11, - 'And the smoke of their torment rises for ever and ever. THERE IS NO REST DAY OR NIGHT for those who worship the beast and his image, or for anyone who receives the mark of his name.' Please could anyone enlighten me?

Chris Date:
Hi BalletBug. I'm encouraged to see that you're nearly convinced of our view, even more encouraged to see that it's helping to solve a profound struggle you were having. I would say that not only does conditionalism have an answer to Rev. 14:11, our answer is far better.

Consider first that the vision contained in Revelation is highly symbolic imagery. As such, one can, as I do, grant that here in the imagery, the eternal torment of beast worshippers is what's talked about in the imagery. But it does not follow that therefore anybody will be tormented for eternity in reality. After all, what are these beast worshippers worshipping? A terrifying seven-headed, ten-horned beast that looks like a lion, a leopard and a bear. Few expect such a beast in reality; this beast is a symbol for something else. As such, the eternal torment of those in the vision who worship the beast is also a symbol for something.

Consider next that elsewhere in Revelation the same imagery is used of smoke rising forever from torment. Mystery Babylon, the great harlot of Revelation 18, is said 3 times to be tormented. And in chapter 19 smoke rises from her forever. There you have it: smoke rising forever from torment. But the angel in chapter 18 tells us that the harlot is a symbol for a city, and that the imagery of her being tormented is symbolism for the city being destroyed. So smoke rising forever from torment in Revelation is symbolism for destruction.

Consider thirdly that this really should be no surprise to the student of the Bible. It came as a surprise to me as I began my study of this topic, which means I wasn't a very good student of the Bible Because smoke rising forever is not new to John and to Revelation. Smoke rises forever from the burning pitch of Edom in Isaiah 34:10, again symbolism communicating that city has been destroyed--even as traditionalists will often acknowledge. It's kind of like the symbol of a mushroom cloud; it tells you how complete and devastating the destruction was. And it's reminiscent of the smoke Abraham sees rising from the remains of Sodom and Gomorrah.

Consider finally that smoke rising forever is not the only symbol that informs us here. Fire and sulfur (brimstone) are used as well, which come from the Sodom and Gomorrah event and from Isaiah 34 (which we just looked at). And drinking from God's wrath is also frequently used in the OT to refer to God's judgment upon people in which they are killed.

So when we combine the facts that (a) this is symbolism, (b) smoke rising forever from torment elsewhere in Revelation symbolizes the destruction of a city, (c) smoke rising forever in the OT is symbolism communicating the destruction of a city and the slaying of its inhabitants, and (d) fire and sulfur and drinking God's wrath also speak of God's judicial slaying of people, we have excellent reasons to understand Revelation 14:9-11 as strong support for conditionalism.

It doesn't challenge our view, it proves it.