The main SkyClub has 3 (maybe 4) shower rooms. The shower rooms have sinks and showers (but no toilets...there are toilets in the normal large restrooms).

They give you one towel and the showers have a "shower gel/body wash" dispenser, but if you are picky about soap/shampoo/conditioner, bring your own.

There is definitely no shirt pressing service and I have never seen any ironing board or iron anywhere in the club.

I believe there is a gym/pool facility in the hotel connected to the terminal. You might want to check that out and even consider getting a day room if ironing your clothes is that important.