Cash Registry help

Hi all,
Thanks for your help in advance!
I am originally from the UK but live in Canada which is where we are getting married.A lot of our extended family cannot fly out for the wedding but have asked where they can send cash or gifts. We were just going to say no gifts anyway because 90% of our wedding party are making such a big effort flying over here but my aunts and uncles who can’t make it are insisting! We already live together so we don’t need actual gifts but are going on a honeymoon to Hawaii so would love some cash towards that.What is the best cash registry you have used and did you have any issues/charges with the payments coming internationally? I’m wondering if it’s just easier to send those few a pay pal or transferwise account instead of adding a registry to our website? I know the fees for these are smaller than a bank transfer but I’m not sure where a cash registry would sit in this. I also don’t want our guests to pay any international fees for sending it! ThanksSarah