That workaround has a lot of drawbacks. But your using Revit LT makes this difficult. Would you explain why you want hide the siding and sheathing layers, as opposed to merely drawing dimension lines which snap to the face of the studs and leaving the finish layers visible?
If you are obliged to make the siding and sheathing invisible, though, and you need a workaround, here is an idea. Rather than remove items from the model and replace them with detail items, I would model what you want the building to truly include, then remove items as necessary. Modelling more and detailing less is a general rule I follow and it has worked well for me. In this case, you could show the floor plan using Coarse detail view, then draw detail lines in the walls where at the outside face of the studs, then connect your dimension lines to those detail lines, then use Masking Regions to hide the finish layers in that view. That way the finish layers are present so they show up in other views, but they are effectively invisible on your floor plan.
Though I must say, this workaround makes me a little nauseous because I don't like "forcibly hiding" things via detail items. That is simply not how Revit is meant to work.
