DH7 should be kept internal, at least at first. Being misinterpreted as trying to construct a straw man when you've been trying to do the opposite can derail a conversation. To actually believe that you've made a steel man, not a straw man, the person you're arguing with would have to admit that you've created a stronger argument for their own position than they could.

It's probably best to practice up to DH7 internally, and only up to DH6 vocally.

If we imagine arguments as soldiers, as they tend to be, the problem becomes even clearer:

(A and B are about to fight.)

A. Ah! My worthy opponent! I shall send my greatest soldier to crush you... GOLIATH! ATTACK!

B. His sword's a little wimpy. Let me give him a bazooka.

If I were A, I wouldn't trust that bazooka on B's word alone, I'd be annoyed at the slight against my blacksmiths, and, even if it turned out to be a totally legitimate bazooka, I would, at the very least, consider B a tactless grandstander.

(Though if the bazooka did work, I'd use it, obviously. I just wouldn't like using it.)