If you can't stop 100% of attacks, then that means it's pointless. Again, it's not the attack, it's the threat of attack that is closing the strait, and you just admit you can't stop their attack 100% regardless of how you degrade their offensive capability.
And as I said before, if you want to hold Iranian oil production hostage (which frankly is the only things going out of the strait now which mean if we actually did it, it will make the oil sitaution worse, not better) all you need to do is to threaten to bomb it, you don't need to invade it to hold it hostage, unless you want to take it over and ship it yourself, which you will then need the strait to open.