Here's what you do;
Just put a bunch of crap ( say, pots, buckets etc) on the basement bed. Worked like a charm.
As for making her wear what you want, here's the thing;
There's 3 basic ways to swap stuff with Npcs, "trade", "purchase" and " pickpocke".
All 3 of which are possible with wives.
Like followers, wives generally wear their default armour, unless you give them even better armour. And their default armour cannot be swaped in any of the above 3 ways, unless they have better armour, in which case they'll move their default armour from their "inventory" to their "store" then you can simply buy their default armour, then even more simply just take back the awesome armour you just gave them. They'll then be in a brownish yellow bikini. Then you can make them wear anything you want. . Oh, you have to let them keep at least one part of their default armour though ( at least in their inventory) otherwise the game will think she's "naked" and return the entire set. I suggest letting her keep either her wristbands or her shoes.
Also, it's the armour level not enchantments that NPCs define as "better". To improve armour you have to take it to a workbench, although I don't think the tarn wench dress can be improved at all.
Short version,; give her dwarf armour or something, buy her default armour, take the dwarf armour back, give her a skimpy dress, then dump crap on her bed. Women LOVE getting treated like that. But let her keep her wristbands.