I have heard that there is a segula for reading pitum ketoret from klaf. What is the specific segula and what are the sources?
This site (which I've never heard of) cites a number of sources for the practice of reciting the paragraph, one of which ostensibly relates to specifically reading it off of קלף, the others of which point out that reading it in general is a סגולה.
The first one is from Seder Hayom, which says
one who fears for himself and for his soul should put great effort into this matter, namely to write the entire text of the ketores (the composition of the incense) on kosher parchment in ksav ashuris (the script in which a sefer Torah is written), and he should read from this scroll daily, once in the morning and once in the evening with great concentration, and I guarantee [that this will help].
The copies of Seder Hayom hosted on hebrewbooks.org have
ולכן ראוי לכן בעל נפש להשתדל בכל עז לאומרה בכ"י פעמיים בבקר ובערב ולכוין בו מלה במלה
ולכן ראוי לכל בעל נפש להשתדל בכל עז לאומרה בכל יום פעמי' בבקר ובערב ולכוין בו מלה במלה
I am no Seder Hayom (or otherwise) scholar, but the first version here could be misread as meaning that it should be read from a manuscript if כ"י stands for "כתב יד", and not "כל יום", which is what appears in all three of the earlier versions. However, none of them mention anything about kosher parchment, כתב אשורית, or a guarantee.
This site gives the citation for the כף החיים in אורח חיים 132:23, which itself cites some other sources including the כף החיים (?), saying that קלף and כתב אשורית are a סגולה for wealth and general success.