Is this what you changed in about:config?

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

More info on about:config: Configuration Editor for Firefox. The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future.

(2) In the search box in the page, type or paste accessiblecaret.en and pause while the list is filtered

Firefox will list two preferences related to this feature.

(3) If the layout.accessiblecaret.enabled preference is bolded and "modified" to true, double-click it to restore the default value of false

(3) Double-click the layout.accessiblecaret.enabled_on_touch preference to switch the value from true to false

If that doesn't work, hmm, I wonder whether there is something unusual about that form field.

BINGO! I completely missed (3); touch was enabled. Changed it to false and the nagging blue tear drops went away. Thank you for the help!

Note that you can modify the height and width of the raindrops and make them smaller. I use them with both set to "11" to be able to see if extra whitespace got selected and adjust the selection with the mouse if I misclick.

layout.accessiblecaret.height = 11.0
layout.accessiblecaret.margin-left = -6.0
layout.accessiblecaret.width = 11.0