The ch digraph in both instances of Eichhörnchen is pronounced closer to the way you pronounce the first consonant in the word "hue". It's closer to the front of the mouth than the one you're thinking of in Irish. It's ç in the International Phonetic Alphabet. It's a different sound than the other way that ch is pronounced in German and has to do with what sounds/letters appear around it. The other pronunciation of ch in German is normally pronounced as x (this sound is the one you're thinking of that's in Irish) or χ.