TF-100 TA Testing...and other??

When testing the TA, the instructions says "one drop at a time, swirling between each drop. Wipe the tip of the bottle after every drop with a damp cloth."

• How critical is it to wipe the tip after every drop with a damp cloth?
• On the CYA test, would it be ok to use the plastic beaker and fill 15ml pool water and 15ml R-0013, while using the Speedstir?
• Also, where can I purchase JUST the Taylor K-2006 case only?
• Last question, has anyone used the Skimmer Angel, and do you...

TF-100 TA Testing...and other??