I dabble in making per fa mues too... most pong,,,but every now and then get one right...
i used to note the proportions,,,
but gave up,,as every thing i did to sums stuffed up,,,so just did it by smell and feel ask Tau,,, she have a very pongy bathroom full of radioactive miasmas
but I think the best things are made impromptue,,and never to be repeated...
