With a 2 hour connection, I wouldn't count on having enough time to take a shower. You could lose time with flight delays, clearance procedures etc. Also, there could be a line for the showers. (At the British Airways lounge in London, I usually have to wait at 30 minutes for a shower cubicle, even though the staff prioritize requests based on customers' flight schedules.)

Other options to deal with the grubbiness factor: (1) Shower right before you leave for the airport. (2) Pack clean undies and socks in your carry-on (always a good idea anyway in case your luggage doesn't arrive with you). (3) If you're travelling in a cabin that doesn't hand out hot washcloths, bring a facecloth of your own for a quick wash in the airplane lavatory. (4) Dress in layers (e.g. tshirt or sleeveless shell plus cardigan) and bring a spare tshirt or shell that you can change into once you arrive in AMS. (5) Listerine breathstrips freshen breath and don't count as liquids. (6) Wear wicking fabrics (especially against your skin). (7) Choose clothes that hide or resist wrinkles and stains (e.g. heathery colours, rather than crisp blacks, whites and navies; stripes rather than solids, etc.) and that have a little stretch (so that you can sleep comfortably) but not too much (so that you don't feel like a sausage in its casing).