#delay-safari-extension, #delay-safari-extension * {
    visibility: hidden !important;
}

#delay-safari-extension, #delay-safari-extension * {
    opacity: 0 !important;
    visibility: hidden !important;
}

Set opacity to 0 to block Flash.
Set opacity to 0 to block Flash.

Some Flash elements, like ads or videos, show even though they're
invisible.
