I agree completely with stinkymice. Firstly bio washing liquid gets cat wee out of anything. Secondly, yes, Feliway is a good idea.
Thirdly and most importantly, provide a litter tray. Even cats who normally go outside often don't like to in bad weather. And if you know there's likely to be a problem when you go away, then certainly make sure there's a tray then.
Our house always stinks of cat when we go away for a few days. Except when we went away over christmas I left one of those cat calm plug in things going. I didn't really expect anything but it worked!! - well once, so I'm not holding my breath but next time we go away I will make sure to plug it in!
I would also suggest having a litter tray in the house if she doesn't like to go out into the rain. I'm sure a good wash or 2 in bio will sort the shirts out, no need to chuck them!!
OK...any thoughts. We have 2 cats, sisters and they have until recently got a long pretty well. One of them (the big one!) seems to be being bullied little bit by the smaller one though and I think that this means that she's stressed when we go away to see family for a few days every 3 months or so. We have neighbours coming in to feed and see them twice a day now to try and stop it but after returning last night we have at least 4 different places where the cat has weed (and poo'd)....washing basket, ironing basket, floor, paper basket...you name it. Both are outdoor cats and have a cat flat (a microchip one so no stray cats inside the house)
She's usually OK if we're around, although if it's raining she has been known to stay and wee on the floor (or in a shoe ) She a bit of a clingy cat and I'm not sure that she's altogether there mentally to be honest.....much as I love her.
I'll be honest, nasty thoughts have crossed my mind....and I dare not tell my husband that she's weed on 4 work shirts and that he may have to replace them all after sitting covered in cat wee for 5 days.