Translate without PO Edit

<?php
function wpf_filter_gettext( $translated, $original, $domain ) {
    if ( $translated == "OLD_TEXT" ) { $translated = "NEW_TEXT"; }
return $translated;
}
add_filter( 'gettext', 'wpf_filter_gettext', 10, 3 );

Remove translation

function remove_translation( $translated_text, $untranslated_text, $domain ) {

$removable_text = 'Ide kerül az eltávolítani kívánt kifejezés.';

if ($untranslated_text === $removable_text ) {
return '';
}

return $translated_text;
}