Related Clues:

• Essential to bring up son's pornography
• It's indecent seeing mother use these openers
• Must shift stain
• In recession corporations producing coarse material
• Cereal and other crop disease marked by powdery black spores
• Bit of dirt, stomach's upset
• 'Not safe for work' stuff
• Black mark getting start of the sum wrong
• Stomachs turned by dirty joke
• Business's ending belly up, getting black mark
• X-rated reading material
• X-rated writing