I suspect there are owls in the bog (jag anar ugglor i mossen) means something is really fishy or suspicious.
Now you have really shit in the blue cupboard (nu har du verkligen skitit i det blå skåpet) means that you have done something that’s so far out of line or with such dire consequences that there is no return away from this. Kinda like a harder way of saying “now you’ve done it”.
To throw water on a goose (Slå vatten på en gås) means to say something that won’t be comprehended or taken seriously by the recipient at all, either because of stupidity or because they are too locked in their mindset.