The DoE Info Bridge has material of interest. I would suggest the search terms" filter expedient or filter improvised.
http://www.osti.gov/bridge/basicsearch.jsp
In particular, NUREG/CR-2958; SAND-82-7084 Expedient methods of respiratory protection. II. Leakage tests. Final report discusses leakage tests on manikins through expedient masks made of t-shirts, washcloth and handkerchief material. You are likely to find related documents on that site. As an aside, they found pantyhose a very effective strapping material to assure a tight seal.
This is available in fulltext on the infobridge.
Title Emergency Protection from Aerosols
Creator/Author Cristy, G.A.
Publication Date 2001 Nov 13
OSTI Identifier OSTI ID: 788898
Report Number(s) ORNL-5519
DOE Contract Number AC05-00OR22725
DOI 10.2172/788898
Other Number(s) TRN: AH200136%%165
Resource Type Technical Report
Resource Relation Other Information: PBD: 13 Nov 2001
Coverage Topical
Research Org Oak Ridge National Lab., TN (US)
Sponsoring Org US Department of Energy (US)
Subject 61 RADIATION PROTECTION AND DOSIMETRY; AEROSOLS; HOUSEHOLDS; RADIOACTIVE AEROSOLS; RADIATION PROTECTION; ELECTRIC APPLIANCES; PRESSURIZATION; AIR INFILTRATION; MITIGATION
Description/Abstract Expedient methods were developed that could be used by an average person, using only materials readily available, to protect himself and his family from injury by toxic (e.g., radioactive) aerosols. The most effective means of protection was the use of a household vacuum cleaner to maintain a small positive pressure on a closed house during passage of the aerosol cloud. Protection factors of 800 and above were achieved.
Country of Publication United States
Language English
Format Medium: ED; Size: 58 pages
System Entry Date 2008 Feb 05