Well, as I have repeatedly noted in a number of posts, I have found it impossible, as a private individual, to buy metaborate in the UK.
I shan't bother with the "Wilde method" again. Though clearly it worked for him and others, I've had two wildly (pun unintentional) inconsistent results now.
For the few occasions when I do need metaborate, I'll substitute 1.5g Hydroxide+7.0g Borax for every 10g required. I've done this recently a number of times now with consistent results.