I cant think of any reason why not. *The Fresca does come with a rubber plug to put in the basket to backflush, admittedly the plug has a small hole in it which I assume (new to all this) a blind filter doesnt, but I would think the hole is to allow some cleaning solution through to the filter rather than a being a pressure relief device. *I would certainly go for it (though not sure why you need to) - if you are not sure, I am think the Breville site has a help facility.
Not sure if I have missed the point of your question but you can certainly backflush the device, and you could use a powder rather than the rather expensive tablets, I am sure.
I got a Fresca last week and can think of nothing but coffee at the moment. *I have a whole new interest in life - the Fresca and *the sample packs of green beans from Beanbay, and a $12 popper from Kmart have created a brand new hobby (rapidly turning into an obsession I fear!). *I am so glad that I stumbled across this site when looking for a replacement for my previous espresso machine which was no longer co-operating.
My wife (not a coffee drinker) is rolling her eyes heavenward and telling me the interest will never last - little does she know! *::)