score:7
In New Zealand tipping (wait-staff or anyone in fact) is not normal nor expected.
Many places like coffee shops have tip-jars if you want to give something extra, but it's not expected. If anything, often all that goes into a tip-jar is coins from change - occasionally someone will put more in.
No one would be offended if you put foreign coins into a tip-jar, however I think the charity collection bins they have in many shops, banks, or museums would be a better place for them (these often say you are welcome to put foreign coins in).
Upvote:3
Tipping on foreign currency is okay if:
Otherwise it would only annoy the server as they'd have to go out of their way to exchange your money, or just throw it out as a useless piece of paper. So to answer your question - no, do not tip in Soles while in New Zealand.