In a moment of brain-fade last night, I over-diluted a batch of developer by a factor of 3 for a roll of 135.
Had I recognised what I'd done before it was fixed, I expect I could have extended the development time and perhaps rescued the situation, but I didn't.

Consequently I have ended up with a roll of negatives bordering on transparent. The edge markings and frame spaces are barely discernible.

I have scanned the roll and managed to extract something, and normally I would write this off to experience and move on, but there are two shots on this roll which I would particularly like to salvage further if at all possible.

I have "read up" what I can on the use of intensifiers, and realise that I can't expect much in the way of increased density with this particular situation, and that I can expect increased grain. The latter is no great concern.

I know I can make my own intensifier, and have found several formulae here at APUG from Ian Grant ... but don't have all the chemicals or a staining developer to hand (plus I would rather not have to buy rather expensive and toxic materials which I will likely use only once in a blue moon)

The choices of commercially easily available intensifiers in the UK seem to be Fotospeed Cl10, and the Speedibrews Chrome Intense and Speedintense. I can't seem to find much information about these, except that the Fotospeed product requires Dektol for the redevelopment step. Speedibrews website refers to the use of Speedintense for "grossly underdeveloped negatives" which is exactly what I have.

Is there anything others can add from experience of these products?