Hi Sean,
I think this may be a bug. I tried to create a spiral with some sparkles and there were no sparkles... Here are my settings:
spirals Effect Settings
username pharout
user_target MT
effect_class spirals
effect_name WTBLUE
handiness L
number_spirals 2
number_rotations .5
spiral_thickness 30
window_degrees 360
frame_delay 50
sparkles_count 25
direction cw
rainbow_hue n
color1 #0000FF
color2 #FFFFFF
color3 #FFFFFF
color4 #FFFFFF
color5 #FFFFFF
color6 #FFFFFF
fade_3d y
show_frame n
seq_duration 12.9
fade_in 0
fade_out 0
speed 1
submit Submit Form to create your effect
$use_background N
background_color #FFFFFF
sparkles 0
batch 0
OBJECT_NAME spirals
and the resulting image is below.
Frank