I am used to toners as DIY scratch mixes. If the vendor wants to keep people afraid of DIY's then prepare concentrated stock solutions of the formulae, and have the end user dilute them.
The bleach is likely pottasium ferricyanide (yellow) which will work reused over and over for quite a lot of prints. When it ceases to bleach a print in a reasonable time you know that you are reaching its exhaustion point. It can be over diluted if you are trying to only partially bleach the print and the 1+4 working bath is acting too quickly.
Water wash/rinse the bleached print to get rid of all the yellow stain; I think Kodak recommends 5 minutes.
The toner is a sulphide type, as the box says - and yep they smell like rotten eggs. The other variety use thiorea and don't smell nearly as bad, but thiorea is a bit on the nasty side, and has the potentiall to chemially fog sensitized silver material as well.
Once dilited the sulphide solution will likely tone at least 20 8x10's per litre, and may be stored between toning sessions. (maybe more if it is at all like Kodak's sepia toner). Oh, and you can dilute the toner to greater than 1+4 (yes, your interpretation of the dilution is correct) if you don't want it to tone as fast.
Then wash the print for I think 20 minutes for FB; less (not sure how much) if toning RC paper.
This, and most toners, can be done in full illumination, so if the smell annoys you, do it outside where the ventilation is improved.
I can't recall, but this toner ( as some do) may need prints a bit overexposed or underexposed to get the 'right' look once they have been toned.
So make test prints that are deliberately off, and experiment, and have some fun.
Most FB papers, particularly warm toned ones, provide a more pronounced image tone change better than others such as cooltine FB and RC in general, but I beleive from my past palyings with it that sepia works pretty well on all paper types.
