[digging]

No?

The only official pronunciation of X in English is "ks", and there are many languages that use X for many different sounds. Shitter is appropriate, I think some Spanish dialects might read it that way.

[madcaptenor]

I don't think X as "sh" in Spanish exists (but I could be wrong). But Mandarin as transcribed in pinyin has it.

Also in English x is pronounced as z at the beginning of some Greek-derived words like Xerox and xylophone.