I'd suggest you visit the appropriate forum at
http://www.dpreview.com and do a search. There may be more than just the type swab and fluid.
Individual cameras may have their own maintenance quirks.
(Nikon SLR Talk, Canon SLR Talk, Sigma ....)
And you might enjoy visiting
http://www.luminous-landscape.com and doing a search using 'Africa'. There are at least three articles about using dSLRs in dusty environments on the site.