Stamp quilt

My mum was a quilter too.
She made some lovely quilts and of course all by hand, because otherwise it wouldn't be a REAL quilt.
We've got a double wedding ring on our bed and this little wall hanging:

It's 72x53 cm with a 4 cm border; in inches: 28"x21"with a border of 1.5".
Each piece is 1x1 cm (0.4"x0.4")
And it's called a stamp quilt because each piece is as big as an old fashioned stamp.

I've been wanting to make something like this and when I saw Oh, Fransson!'s tutorial on it I was very pleased. Except for the fact you wouldn't be able to use it as a quilt because of the interfacing she used.

Here's the quilt I mean by Oh, Fransson!
And here's her tutorial.

So I had to find some interfacing that doesn't stay on, like  a water soluble?
Floriani has a solution: Stitch N Wash Fusible.
Do you have any experience with it? If so, please share your knowledge here.

What I've done so far is cut a number of 1.5" pieces and sewn a few together using this interfacing.
I looks like this on my sewing board.

It's tiny and thus comes close to the dimensions I wanted.
I'll make a 1.5" version too, to see which will look better.
And I'm not sure about the choice of fabric/colour.
This could be an abandoned project in the making ... we'll see.

Just in case you have thought of a name for my brown/cream quilt from my last post: PLEASE tell me.
My mind has gone blank(ety blank)

Have a great week!!